IE8: RadioButton tab order wrong

[Douglas Hays]

Load test_CheckBox.html in IE8. TAB thru the radio button group containing news/talk/weather. The widget "news" is focused but "talk" should have been since it's checked. This is affecting a11y compliance. Seems to be related to IE not properly processing the checked attribute until the node is attached to body (after startup()) but the attributes are applied before startup().

[Douglas Hays]

In [30457]:

Refs #16621. Process checked in startup() to make IE happy. Added automated test.

[bill]

Starting with [30457] dijit/tests/form/CheckBoxMixin.html is getting four failures on IE8.

[Douglas Hays]

In [30462]:

Refs #16621, #16512. Blank RadioButton? value was being set to "on" after reset which is incorrect (but correct for CheckBox? widgets). Removed unnecessary set/removeAttribute(checked) calls since only domAttr.set is needed for the checked attribute. Don't call domAttr.set if already set correctly to keep IE from losing tab order. Added automated tests.

[bill]

[30462] break the "radio group tab order" test on CheckBox_a11y.html on IE8.

[Douglas Hays]

In [30469]:

Refs #16621, #16512. Cannot specify CHECKED in the CheckBox? template since this messes up IE6-8 radio button tab order. Instead run setAttribute('checked','checked') in postCreate. Added additional automated test.

[Douglas Hays]

In [30476]:

Refs #16621. Backport r30457, r30462, r30469 to 1.8.

[Douglas Hays]

Deferring the backport to 1.7 since it's higher risk.